Separation of mixed-sulfid ores.



HENRY LAVERS, OF SURREY HILLS, VICTORIA, AUSTRALIA, ASSIGNOR TO MINERALS SEPARATION AMERICAN SYNDICATE (1913) LIMITED, OF LONDON, ENGLAND.

SEPARATION OF MIXED-SULFID ORES.

No Drawing.

To all whom it may concern:

Be it known that I, HENRY LAVERS, a subject of the King of England, residing at Canterbury Road, Surrey Hills, State of Victoria, Australia, have invented certain new and useful Improvements in'the Separation of Mixed Sulfid Ores, of which the following is a specification.

This invention relates to improvements in ore concentration and has for its object the separation ofvarious metallic sulfids from each other by means of flotation separation. In this specification the word ores is intended to include concentrates, tailings, slimes or other products containing mixed metallic sulfids.

The present invention is a modification of that described in the previous United States Letters Patent to Greenway. & Lowry No. 1,102,738 granted July 7, 1914. In that specification it is pointed out that if a salt of chromium (sucli as sodium bichromate or potassium bichromate) is introduced in solution into the circuit liquors in the agitationfroth process, or if the material to be treated is subjected to the action of such chromium salt solution by digestion or otherwise whereupon the material is subjected to flotation treatment, it is possible to obtain a flotation product relatively high in certain sulfids on the one hand and a residue relatively high in other sulfids on the other hand.

It is now found in treating finely pulverized material containing mixed sulfids par- I ticularly good results can be obtained if the pulp during digestion with the chromium salt in solution, and/or during flotation treatment with the chromium salt in solution, is slightly alkaline. pulp may advantageously contain an amount of sodium carbonate equivalent to 1% by weight on the ore in the pulp.

A further feature of this invention is as follows: I have found that if the finely pul verized ore containing mixed sulfids and suspended in slightly alkaline water is subjected to the agitation-froth process with the use of a suitable frothing agent a flotation product can be obtained containing the bulk of the metallic sulfids which are'thus separated from the gangue which mainly sinks. It is then found that if the concentrates be re-treated by the agitation-froth process (still in alkaline circuit) and with the addition of a salt of chromium, or after Specification of Letters Patent;

Application filed May 28, 1914. SerialNo. 841,477.

For example the Patentedifune 15, 1915.

digestion with such chromium saltsolution,

of zinc and 14.2% of iron,'was very finely crushed and .then subjected to froth-flotation treatment in apparatus of well-known type by being vigorously agitated with four times its weight of water at 130 F. containing in solution sodium carbonate amounting to about 22 lbs. per ton of ore, sodium bichromate amounting to about 6 lbs. per ton of ore, eucalyptus oil amounting to about 1} lb. per ton of ore and kerosene amounting to about lb. per ton of ore. The flotation product obtained from this operation consisted of a concentrate containing 50.1% of zinc, 4.25% of lead and 8.3% of iron while the bulk-of the iron and lead were left in the residue.

(2) Slimes containing about 11.6% of lead and 13. 1% of zinc were introduced into an agitating apparatus together with four it is possible to obtain a flotation product a times their weight of water containing in solution carbonate of soda equivalent to 24 lbs. per ton of slimes to which was also added eucalyptus oil equivalent to about 1 lb. per ton of slimes at a temperature of about 130 F. The floating concentrate con tained 22.2% of lead and 27.4% of zinc. The concentrate was then subjected to differential bichromate flotation, that is to say, the concentrate was subjected to flotation treatment of water at about 130 F. contain-' ing sodium carbonate equal to about 24 lbs. per ton of concentrate, sodium bichromate equal to 6 lbs. perton of concentrate, keroin subjecting the ore to the action of a chromium salt in a slightly alkaline solution and to a flotation separation whereby a flotation product relatively high in certain of fineness, then subjecting the crushed ore Y to a flotation separation in the presence of a solution of a salt of chromium and in a hot slightly alkaline circuit, whereby a flotation product relatively high in certain sulfids and a residue relatively high in other sulfids are obtained.

4. The hereindescribed process of concentrating metallic sulfid ores which consists in first crushing the ore to a suitable degree of fineness, then subjecting it to an agitation froth process of ore concentration in a slightly alkaline circuit for the formation of a froth containing the bulk of the me tallic sulfids and thereafter subjecting the concentrate to a flotation separation treatment in the presence of a solution of a saltof chromium and in a slightly alkaline circuit whereby a flotation vproduct relatively high in certain sulfids and a residue relatively high in other sulfids are obtained.

5. The hereindescribed process of concentrating ores containing zinc and lead sulfids consisting in first crushing the vore to 'a suitable degree of fineness, then subjecting the said ore to a flotation separation treatment in the presence of a solution of a niaaeai the said ores to a flotation separation treatment in the presence of a solution of bi chromate of sodium and in a slightly alkaline circuit whereby there is produced a flotation product relatively high in zinc and low in lead and a residue relatively high in lead and low in zinc.

7. The hereindescribed process of concentrating ores containing-zinc and lead sulfids consisting in first crushing the ore to a suit able degree of fineness, then subjecting the said ores to a flotation separation in the presence of a solution of sodium carbonate and bichromate of sodium whereby thereis produced a flotation product relatively high in zinc and low in lead and a residue relatively high in lead and low in zinc.

8. The hereindescribed process of concentrating ores containing zinc and lead sulfids consisting in first crushing the ore to a suitable degree of fineness, then subjecting the said ores to a flotation separation in a hot circuit in the presence vof a solution of sodium carbonate and bichromate of sodium whereby there is produced a flotation product relatively high in zinc and low in lead and a residue relatively high in lead and low in zinc.

In testimony whereof T have signed my name to this specification in the presence of two subscribing Witnesses.

HENRY LAVERS.

Witnesses:

CHARLES NICHOLAS COLLISON, 'M. A. Ennnnr. 

